Experimental evaluation of ultra wideband propagation and transmission within a spacecraft for replacing wired interface buses

Ultra wideband (UWB) technology has been expected to communicate in very high data rates by wireless within closed environments, such as spacecrafts. With a view to replacing onboard wired interface buses by wireless connection, UWB and narrowband propagation were measured in a UWB frequency band (from 3.1 to 10.6 GHz) within a small spacecraft. While narrowband propagation resulted in considerable spatial variations in path gain due to interferences caused by multipaths, UWB yielded nearly no fading. This suggests that the UWB systems have an advantage over narrowband from a viewpoint of reducing fading margins. Propagation gains were measured with full-, low-, and high-band UWBs, and narrowband (20 MHz bandwidth) for various antenna settings and polarization configurations for transmission and reception. Polarization configurations were found to produce almost no effect on average power delay profiles. Throughputs were also measured with a WiMedia UWB device. More than 85-Mb/s throughputs were observed for all antenna settings and propagation configurations.